Gas Turbine Vane Platform Cooling Film and Sealing
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Solution Overview
Problem
Existing gas turbine designs face inefficiencies in cooling the vane platform due to non-uniform static pressure distribution, leading to hot gas leakage and overheating, which requires excessive air for cooling and is challenging to manufacture with complex shaping requirements.
Innovation Solution
The design incorporates cooling ducts within the combustor walls, tilted at specific angles relative to the rotor axis, to create a synergistic cooling effect with purge air, sealing the gap and reducing air usage by enhancing the cooling film efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If cooling air is injected through the interface gap to cool the vane platform, then the vane platform is cooled, but excessive air is consumed and hot gas leakage occurs
Solution Approach 1:
The invention introduces a sealing film of cooling air upstream of the interface gap between the combustor and vane platform. This sealing film is created before the hot gas can reach the gap, preventing hot gas leakage into the gap and reducing the amount of air needed for cooling the vane platform. The sealing film acts as a preliminary protective layer that blocks the harmful hot gas flow.
Solution Approach 2:
The cooling system is divided into two distinct functions: a sealing film function (preventing hot gas leakage) and a cooling function (cooling the vane platform). By segmenting the cooling air flow into these two purposes and controlling them separately, the system achieves efficient cooling with reduced air consumption.
2Object-affected harmful factors
If purge air is injected through the gap to prevent hot gas entry, then hot gas leakage is prevented, but excessive air is consumed
Solution Approach 1:
The sealing film is introduced upstream of the interface gap to prevent hot gas from reaching the gap in the first place. This preliminary action eliminates the need for large amounts of purge air to be injected through the gap, as the hot gas is already blocked by the sealing film before it can cause overheating.
Solution Approach 2:
The invention converts the potentially harmful hot gas flow into a beneficial sealing film flow. By directing a controlled amount of cooling air to create a sealing film, the system prevents hot gas leakage more efficiently than traditional purge air methods, reducing overall air consumption.
3Object-affected harmful factors
If bumps are added to the vane platform to increase static pressure and reduce hot gas re-entry, then hot gas leakage is reduced, but manufacturing complexity increases
Solution Approach 1:
The invention extracts the pressure control function from the vane platform itself and relocates it to the cooling air injection system. Instead of modifying the platform geometry with bumps, the sealing film of cooling air is used to control the pressure distribution and prevent hot gas re-entry, simplifying the platform design.
Solution Approach 2:
The sealing film acts as an intermediary between the cooling air and the hot gas flow. Rather than directly modifying the platform structure to control pressure, the sealing film mediates the interaction between cooling air and hot gas, achieving pressure control and hot gas prevention without complex platform shaping.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This configuration significantly improves cooling efficiency, reducing the amount of air needed for cooling while maintaining manufacturing feasibility by optimizing the tilt angles and geometry of the cooling ducts, resulting in improved thermal management and reduced air leakage.
Implementation Method 1
The air injected through the interface gap flows into the hot gas path and provides a cooling film on the vane platform
Implementation Method 2
one or more cooling ducts arranged upstream of the gap and within the inner and/or outer combustor walls
Data Source
AI summary
The present invention relates to a gas turbine implemented for example at the interface between the combustor and the vane platform. An efficiency of a cooling film associated to the vane platform can be increased, hence reducing the quantity of the air needed.